摘要
在不同组成的焙烧气氛中制备了氧化铝载体,对其进行XRD、压汞和SEM表征。将载体浸渍在银氨络合溶液中制得银催化剂,对制备的催化剂进行CO脉冲吸附和O 2-TPD表征,并采用固定床反应器对比评价了反应性能。结果表明,空气混合氮气气氛下焙烧的载体,孔径呈多级分布,氧化铝微观形貌呈“块”状。氮气比例的提升,有利于Ag颗粒的分散和提高催化剂表面低温脱附氧的比例。以70%空气+30%氮气气氛所焙烧载体制备的催化剂相比传统空气焙烧气氛,反应温度降低1.7℃,选择性提高1.6%,但更高的氮气比例会造成催化剂的性能劣化。
Alumina carriers were prepared using different roasting atmospheres,and were characterized by XRD,mercury intrusion,and SEM.Ag catalysts were prepared by dipped carriers in silver ammonia complex solution.The prepared catalysts were characterized by CO pulse adsorption and O 2-TPD,and the reaction performances were evaluated using a fixed-bed reactor.The results showed that the carriers roasted in an air-mixed nitrogen atmosphere had a multi-stage pore size distribution,and the microstructure presented“lump”shape.Increasing the volume ratio of N 2 in the roasting atmosphere could improve the dispersion of Ag particles and increase ratio of low-temperature desorption O 2 on the catalyst surface.Compared withair roasting atmosphere,catalyst prepared by using carrier roasted in 70%air+30%N 2 increased selectivity by 1.6%and decreased reaction temperature by 1.7℃.Higher volume ratio of N 2 would cause deterioration of catalyst performance.
作者
南洋
谢元
全民强
赖喜江
黄鑫
魏珍妮
Nan Yang;Xie Yuan;Quan Minqiang;Lai Xijiang;Huang Xin;Wei Zhenni(PetroChina Lanzhou Petrochemical Research Center,Lanzhou 730060,Gansu,China;PetroChina Dushanzi Petrochemical Company,Dushanzi 833000,Xinjiang,China)
出处
《工业催化》
CAS
2020年第8期37-41,共5页
Industrial Catalysis
基金
中国石油重大技术现场试验项目(2019F-23)。
关键词
催化剂工程
焙烧气氛
α-氧化铝载体
银催化剂
环氧乙烷
乙烯环氧化
catalyst engineering
roasting atmosphere
α-alumina carrier
silver catalyst
ethylene oxide
ethylene epoxidation
